As generally known in the art, various services are provided via mobile communication networks in line with rapid development of technologies associated with computers, electronics, and communications. The most basic type of mobile communication service is a voice communication service, which enables users to communicate via mobile communication terminals regardless of time and place. In addition, a text message service complements the voice communication service. A wireless Internet service has recently been provided and enabled users of a mobile communication terminal to access the Internet via mobile communication networks.
As a result, subscribers to a mobile communication service can not only communicate with desired partners regardless of time and place, but also receive various types of daily information (e.g. news, weather, sports, stocks, exchange rate, traffic) in the form of texts, voices or images via wireless Internet access.
Due to the recent development of communication technology, mobile communication services are shifting from voice communication services to multimedia communication services for transmitting circuit data or packet data, for example. Recently, the IS-95C network has evolved from conventional IS-95A and IS-95B networks and is capable of providing wireless Internet services at a data transmission rate of up to 307.2 Kbps, which is much faster than that supported by the conventional networks (14.1 Kbps and 56 Kbps). Particularly, IMT-2000 services can not only improve the quality of conventional voice communication and WAP services, but also provide various multimedia services (e.g. audio on demand, video on demand) at a higher rate.
Recently, ringback tone or color ringback tone services are drawing much attention. These services provide originators with various sound sources, which have been selected by recipients, as a ringback tone via a communication terminal. Particularly, conventional ringback tones, which are mechanical and monotonous, are replaced with various types of music or sound (e.g. popular music, sound of nature), which have been recorded by recipients. Upon hearing these novel ringback tones, originators get special impressions.
However, current ringback tone services have a problem in that outputted sound sources do not have excellent quality and, if a frame is lost while sound source data is transmitted for providing a ringback tone, mobile communication terminals cannot recognize the loss. This results in erroneous decoding.